Why can’t you tap your helmet...

Tampa Bay Rays infielder Taylor Walls was ejected Sunday in the ninth inning of a 1-0 loss to Houston and had to be restrained during a prolonged argument.

Walls appeared to tap his helmet after taking a called strike, leading to the ejection and to him having to be restrained from going after the home plate umpire.

So why was Walls ejected from the game?

A batter tapping their helmet was the signal for challenging a call when the Automated Ball-Strike System was used during spring training in Major League Baseball. The system is still in use in minor league games, but is not currently being used in regular season games in MLB. used.

Though not explicitly against MLB rules, umpire Nic Lentz seemed to take issue with the gesture. The clash escalated from there, with Tampa Bay manager Kevin Cash coming out to talk to Lentz and try to keep Walls away from him.

Walls was walked back toward the dugout before breaking free and charging at a couple umpires who were in the home plate area. He was quickly grabbed from behind by first base coach Michael Johns, and this time Rays outfielder Josh Lowe walked him back to dugout.

Christopher Morel replaced Walls at the plate and went down swinging for the second out of the ninth.